Ischemic heart disease causes mitral regurgitation by the combination of ischemic dysfunction of the papillary muscles, and the dilatation of the left ventricle that is present in ischemic heart disease, with the subsequent displacement of the papillary muscles and the dilatation of the mitral valve annulus.
Dilation of the annulus of the mitral valve prevents the valve leaflets from fully coapting when the valve is closed. Mitral regurgitation of blood from the left ventricle into the left atrium results in increased total stroke volume and decreased cardiac output, and ultimate weakening of the left ventricle secondary to a volume overload and a pressure overload of the left atrium. U.S. Pat. No. 7,431,692 to Zollinger et al. describes an adjustable support pad for adjustably holding a tensioning line used to apply tension to a body organ. The adjustable support pad can include a locking mechanism for preventing slidable movement of the tensioning element in one or both directions. The locking mechanism may include spring-loaded locks, rotatable cam-like structures, and/or rotatable spool structures. The adjustable support pad may be formed from rigid, semi-rigid, and/or flexible materials, and may be formed to conform to the outer surface of a body organ. The adjustable support pad can be configured to adjustably hold one or more separate tensioning lines, and to provide for independent adjustment of one or more tensioning lines or groups thereof.
U.S. Patent Application Publication 2007/0016287 to Cartledge et al. describes an implantable device for controlling shape and/or size of an anatomical structure or lumen. The implantable device has an adjustable member configured to adjust the dimensions of the implantable device. The implantable device is housed in a catheter and insertable from a minimally invasive surgical entry. An adjustment tool actuates the adjustable member and provide for adjustment before, during or after the anatomical structure or lumen resumes near normal to normal physiologic function.
U.S. Patent Application Publication 2004/0236419 to Milo describes methods for reconfiguring an atrioventricular heart valve that may use systems comprising a partial or complete annuloplasty rings proportioned to reconfigure a heart valve that has become in some way incompetent, a pair of trigonal sutures or implantable anchors, and a plurality of staples which may have pairs of legs that are sized and shaped for association with the ring at spaced locations along its length. These systems permit relative axial movement between the staples and the ring, whereby a patient's heart valve can be reconfigured in a manner that does not deter subtle shifting of the native valve components. Shape-memory alloy material staples may have legs with free ends that interlock following implantation. Annuloplasty rings may be complete or partial and may be fenestrated. One alternative method routes a flexible wire, preferably of shape-memory material, through the bights of pre-implanted staples. Other alternative systems use linkers of shape-memory material having hooked ends to interengage with staples or other implanted supports which, following implantation, decrease in effective length and pull the staples or other supports toward one another so as to create desired curvature of the reconfigured valve. These linkers may be separate from the supports or may be integral with them and may have a variety of shapes and forms. Various ones of these systems are described as being implanted non-invasively using a delivery catheter.
U.S. Patent Application Publication 2005/0171601 to Cosgrove et al. describes an annuloplasty repair segment and template for heart valve annulus repair. The elongate flexible template may form a distal part of a holder that also has a proximal handle. Alternatively, the template may be releasably attached to a mandrel that slides within a delivery sheath, the template being released from the end of the sheath to enable manipulation by a surgeon. A tether connecting the template and mandrel may also be provided. The template may be elastic, temperature responsive, or multiple linked segments. The template may be aligned with the handle and form a two- or three-dimensional curve out of alignment with the handle such that the annuloplasty repair segment attached thereto conforms to the curve. The template may be actively or passively converted between its straight and curved positions. The combined holder and ring is especially suited for minimally-invasive surgeries in which the combination is delivered to an implantation site through a small access incision with or without a cannula, or through a catheter passed though the patient's vasculature.
The following patents and patent application publications, relevant portions of which are incorporated herein by reference, may be of interest:    PCT Patent Application Publication WO 07/136783 to Cartledge et al.    U.S. Pat. No. 5,306,296 to Wright et al.    U.S. Pat. No. 6,569,198 to Wilson et al.    U.S. Pat. No. 6,619,291 to Hlavka et al.    U.S. Pat. No. 6,764,510 to Vidlund et al.    U.S. Pat. No. 7,004,176 to Lau    U.S. Pat. No. 7,101,395 to Tremulis et al.    U.S. Pat. No. 7,175,660 to Cartledge et al.    U.S. Patent Application Publication 2003/0050693 to Quijano et al    U.S. Patent Application Publication 2003/0167062 to Gambale et al.    U.S. Patent Application Publication 2004/0024451 to Johnson et al.    U.S. Patent Application Publication 2004/0148021 to Cartledge et al.    U.S. Patent Application Publication 2005/0288781 to Moaddeb et al.    U.S. Patent Application Publication 2007/0080188 to Spence et al.
The following articles, which are incorporated herein by reference, may be of interest:    O'Reilly S et al., “Heart valve surgery pushes the envelope,” Medtech Insight 8(3): 73, 99-108 (2006)    Dieter R S, “Percutaneous valve repair: Update on mitral regurgitation and endovascular approaches to the mitral valve,” Applications in Imaging, Cardiac Interventions, Supported by an educational grant from Amersham Health pp. 11-14 (2003)    Swain C P et al., “An endoscopically deliverable tissue-transfixing device for securing biosensors in the gastrointestinal tract,” Gastrointestinal Endoscopy 40(6): 730-734 (1994)    Odell J A et al., “Early Results of a Simplified Method of Mitral Valve Annuloplasty,” Circulation 92:150-154 (1995)